Shock mounting for solenoids



March 2, 1954 w, JENCKS 2,671,187

SHOCK MOUNTING FOR SOLENOI DS Filed Jan. 2, 1952 INVENTOR. you/s 4dE/7CK5 6% 6" PMf/ Patented Mar. 2, 1954 SHOCK MOUNTING FOR SOLENOIDSHollis W. Jencks, Detroit, Mich., assignor to doing business as DetroitCarlos 0. Cleverdon,

Detroit, Mich.

Coil Company,

Application January 2, 1952, Serial N 0. 264,448

11 Claims. 1

This invention relates to solenoid types of electro-magnets andparticularly to improvements in a shock mounting for the armature ofsuch solenoids. This invention constitutes a further improvement of thetype of solenoid assembly illustrated and described in my co-pendingapplication for U. S. Patent, Serial No. 171,369, filed June 30, 1950.

An important object of the present invention is to provide an improvedsolenoid construction and particularly to provide an improved assemblyof parts for the solenoid which is highly efiicient in absorbing theshock of the impact of the solenoid plunger or armature. Anotherimportant object of the invention is to provide an improved solenoidconstruction which is designed in a novel manner to absorb the shock ofimpact of the armature at both ends of its stroke, the shockabsorbing'mediums employed for such purpose being so arranged andlocated that they obtain the desired cushioning effect withoutappreciably increasing the overall dimensions of the solenoid. A furtherimportant object of the invention is to provide a novel shock absorbingmounting for cushioning the impact of the armature or plunger againstthe stator or core frame of the solenoid which reduces wattage loss andthe amount of heat generated by the solenoid. A still further importantobject of the invention is to provide a shock absorbing mounting forcushioning the impact of the armature against the core frame which iseasy to assemble and places the cushioning medium under initialcompression.

In carrying out the objects of the invention, a solenoid constructed inaccordance with this invention includes as the major operating elementsa coil winding, a stator or core structure enclosing the coil winding onat least two sides thereof, and an armature or plunger reciprocable inthe coil winding. The shock absorbing means of the solenoid includes aback stop plate which extends across the path of movement of thearmature or plunger in position to be struck thereby at one end of itsstroke. The back stop plate cooperates With side plates secured to thecore structure to absorb the shock of impact of the plunger against theback stop plate. The shock absorbing means further includes a yieldablemember or pad arranged in a novel manner for absorbing the impact of theplunger against the core frame at the opposite end of its stroke. Theresilient member is interposed between the core structure and a baseplate utilized for securing the solenoid to a fixed support. The baseplate 2 together with the resilient member are detachably connected tothe core structure for convenient assembly and disassembly and in anovel manner such as to place the resilient member under compression.The parts are so interconnected that a unitary assembly results which iscompact, durable and capable of being readily disassembled forreplacement of parts.

The yieldable member provided for cushioning the impact of the plungeragainst the core frame is preferably in the form of a pad composed ofresilient insulating material. The pads location serves to float thecore frame on the base plate. This has the added advantage ofeliminating the shorting of the laminations of the core frame therebyreducing wattage loss and the amount of heat generated by the solenoidunit. The core frame, pad and base plate are joined into a unitaryassembly by a novel form of a one-piece metallic spring strap whichholds the pad firmly in place and under slight compression.

Various other objects, advantages and meritorious features of theinvention will become more fully apparent from the followingspecification, appended claims and accompanying drawings wherein:

Fig. 1 is an exploded perspective view of the parts of a solenoidconstructed in accordance with this invention,

Fig. 2 is an end elevation of the core structure of the solenoid in Fig.1 showing the base plate and shock absorbing pad. assembled thereon, and

Fig. 3 is a side elevation of the assembled solenoid of Fig. 1 partlybroken away in section.

The present invention relates to improvements in the type of solenoiddisclosed in the U. 8-. Patent No. 2,466,592, dated April 5, 1949, andin the solenoid assembly disclosed in applicants co-pending applicationfor U. S. patent Serial No. 171,369, filed June 30, 1950.

In the embodiment of the invention illustrated in the drawing, theelectro-magnetic device or solenoid comprises a magnetic stator or framein the form of a core structure generally indicated at It and having asubstantially C-shaped configuration. The core frame it is formed of amultiplicity of soft iron laminations as is the conventional practice.The core frame H] exhibits a central aperture i2 opening through theopposite sides thereof and is further provided with a smaller passage orslot M opening out through the upper end of the frame. The result is aC-shaped configuration as shown in Fig. 2 but it is understood that theinvention is applicable to other types of core structures.

Removably received in the central aperture 12 of the core frame is aseparate energizing coil unit generally indicated at US. As described inthe aforesaid U. S. Patent No. 2,466,592, the coil winding is providedwith a central passage therein which opens out through either one orboth of the opposite ends thereof. The coil unit is removable slidablyinserted through one side of the core frame in the manner described inthe aforesaid patent and is mounted with its central passage aligningwith the passage or slot [4 of the core frame. An armature in the formof a reciprocating plunger generally indicated at is constitutes themoving part of the assembly and in accordance with the customarypractice it may be built of a multiplicity of relatively thinlaminations of magnetic material. In the illustrated embodiment of theinvention the plunger is shown as T shaped having a shank portion 29 anda widened head, portion 22.

A base plate 24 is provided for supporting the assembly thus fardescribed and as shown in the drawing is located. on the side of thecore frame Ill opposite to the slot 14 thereof. The base plate has alateral dimension in one direction greater than the width of the coreframe so that opposite marginal portions 26-26 thereof project beyondthe opposite sides of the core frame. Holes 28 are provided in themarginal portions for facilitating attachment of the solenoid to anysuitable support. The base plate may he further provided with a centralhole located in alignment with the opening or slot 14 and through whicha stem portion 32 or the plunger may project.

Associated with the solenoid and formii able parts thereof are twogenerally sin formed side plates generally indicated at 3 These sideplates are preferably similar in shape and formation to one another andfollow the general contour of the side frame against which they abut inassembled position. Each side plate is provided with the central opening33 which may be of the rectangular formation shown Fig. l and furtherprovided with a pair of holes 33-38 located on opposite sides thereof.The holes 35-33 align with holes it formed in the core frame which mayextend completely therethrough and open out on the opposite sidesthereof. A pair of bolt members 42-42 are provided for extending throughthe holes 38- of the side plates and completely through the holes l?) ofthe core frame in the manner shown in Fig. 3. By means of nuts M-Mtogether with lock washers on the extremities of the bolts, the s.plates are tightly held against the core frame the manner shown in 3. Inthe final assembled position of the parts, the coil winding it projectsthrough the central opening 36 of each side plate.

As shown and described in the aforesaid patent, the coil unit it may beprovided with a sleeve lining disposed in the central passage thereofand through which the shank portion of the plunger reciprocates.

The upper end of such a sleeve lining is shown at 48 projecting abovethe coil unit and entering the transverse opening or slot it of the coreframe. Since the sleeve liner -13 projects slightly from the oppositesides of the core frame to as indicated. in Fig. 1, the side plates 34-31 are preferably cut away or recessed on their inner faces as indicatedat 59 for accommodating the sleeve lining in order to bring the sideplates flush against the core frame.

For cushioning the impact of the armature or projecting portions plungerit at one end of its stroke, there is provided a back member whichextends over the head portion 22 of the plunger and is resiliently 0G3?pl view of Fig. l, the back stop member is indicated at 52 and comprisesa flat metal plate which a width suificient to straddle or bridge thespace between the side plates. The plate 52 is provided with similardepending wall portions iii-5d on opposite sides thereof which extend injuxtaposed relation to the side plates 34-34. The depending wallportions 541-5 are shaped to cooperate with the side plates to absorbthe shock of the impact of the plunger against the back stop plate ashereinafter des ribed.

Inter-posed between the back stop plate 52 and the side plates 34-34 aretwo similar bodies of resilient compressible cushioning materialindicated 553-56. Each elongated body is in the form of an elongatedfiat narrow strip of rectangular cross section. In assembled positionthese strips of resilient material serve to absorb the shock of theimpact of the plunger upon the back stop plate 52 and they may becomposed. of any suitable material for this purpose such as syntheticrubber or leather, or a composition combining both of these materials.

The back stop plate 52 is shaped so receive the resilient strips 55-55and support the latter out of contact with the plunger and in positionto oompressively engage the side plates 34-34. For this purpose, thedepending side wall portions 54-55 of the back stop plate are similarlyshaped at their lower ends to provide the laterally which extend firstoutwardly and thence upwardly to form correspondingly shaped flanges58-58 along each side of the back stop plate. As a result of thisconstruction, the opposite sides of the back stop plate are shaped toform upwardly opening channels each capable of receiving one of theresilient compressible str'ps In the assembled position of the parts, aswill be described more particularly hereinafter, each strip 56 isreceived in its respective channel as shown in Fig. 3 with onelongitudinal edge thereof bearing against the bottom of the channel andthe opposite long tudinal edge thereof substantial abutting the upperedge of the adjacent side plate.

As illustrated herein, the turned down side portions 54-54 of the backstop plate extend between the core frame l0 and the upper portions ofthe side plates 34-34. To accommodate these turned down portions and toprovide a relatively smooth exterior to the device, the upper endportions of the side plates are displaced outwardly relat ve to the coreframe in order to provide the necessary clearance .therebetween to:receive the turned down portions 54-54 of the back stop plate. As shownat 60, each side plate is provided with a jog which offsets the plane.of its upper end portion outwardly laterally relative to its lower endportion.

The back stop plate 52 is interlockingly engageable with the upper endsof the side plates 34-34 and supported thereby across the path ofmovement of the plunger and in position to be struck by the latter atthe end of its outward stroke. To provide interlocking engagement, theupper end portion of each side plate 34 is provided with an elongatedopening or slot 62 which extends substantially parallel to the upperedge. The opening 52 of each side plate has .a longitudinal dimensionslightly greater than the adjacent channel shaped flange of the backstopeted to the side plates a t-3t. In the ex- 5 member but: a;widthpslighthr less thanithe depending; W211l154: and, the; flangeitiof; each chane ne1;.as;shown in Fig-.31 Thed-imensiona-l relation ot'the: elements: such; that the: flanges d3-5h of; the: back: stop; membercannotxbei hitroduced. into the; openings; on slots 62:1oy: a straight:line" mot-ion. Howeveneach fiangedaedge ot the: back" stop-plate can: heinterengaged with; each opening fil of the siderplaterby initiallyincliningone alt-an: acute; angle: toe the? plane off the other to; hookthe upper end of the; side plate: in: to: the. channeli shapedi flangeor the: back stopa plate. and: thenlthereafiter swinging: thesidepplate. toiai position: perpendicular to the: back stop: plate;

In the final assembledposition. of: the. parts the two; side platesate-3,4 extend vertically and: the back; stop plate 52: extends:horizontally and: is supported by" the; side plates" in bridging relaxtion: over armature plunger 1:85. In this: manner; the: backstop plateis. floatingly supported, by the side; plates: across: the path 01?movement of: the: plunger: in position: to be struck." by the headportion Zia-thereof, when the plunger is: retracted.

Eor; cushioning; the impact of thee armature or plunger, til at theopposite end of its stroke, there; is provided: a body in; the form of arela-- tively fiat; resilient; member or pad dd which. is interposed:between. the. base plate 2'4 and; the. bottom sideofi the core frame:in. The pad ii liis preferably of rectangular formation as shown and.of. a size to underlie the coreframe with little or-none or the materialof the. pad. rojecting: outwardly beyond theiframe. The stator orcoreframe is; provided. on. opposite sides with dependingportionsltlsrwhichv overlap the cushionpad? 6 and. serve to; retain the. same:in placeagainst; lateral displacement: dnr'ng operation. of the: device.This is: shown insl li'gs. 1' and 3'.

For convenient. assemblyand disassembly; as: well;' as tov place theresilient. pad 5'4 under initial; compression, there is: provided afastenert't of the: U-shaped character shown in: Fig. 1' which: isproportionately designed to tit around the base plate 2 3 and hook: on,to the upper end or the core frame. Thefastenerispreferablyameta strapof spring: steel: bent into. thev U-shape form illustrated in Figs; 1and: 2 and includes an intermediate base portion; 88 and two: similarupstand'w ins parallel side:.portions.7-1l'-'iil The upper or outer-endsof the side portion s01" l'egs l'lle tfl are shaped for detachableengagement with the core-. frame lfil and as: shown! are: turnedinwardly at ti-22 to the hooks. To receive these hooks, the upper end ofthe: core frame It is: provided with a. pair of correspondingly formedtransverse. grooves: MY-M situated inside of its: outermost; dimensions.and in position to receive. the; rolled?v over: ends 12- -J;2 of thestrap;

To hold the; fastener or strap againstiaterah movement relative tothe.baselplat'ev 2 5, the latter may" be; provided with a.longitudinalgroove i 8 cut? into the. underside'thereot and extending:from one edge to: the opposite edge thereof as: shown in Figs. 1 and 2*.This groove-ispreierablp of thesame dimension and thickness as thebaseportion: 680i the metallic' strapso -that when-the latter isreceived within the groove it does: not

project beyond? the bottom side of the base plates, Furthermore; thesideedges of the base plate through which the; groove: I56 opens may:he. cutaway slightly'asxatfifi to receive fireside portions unless uh-1oorthametaliic strain as. bring the latter: within, the; OQQQSihBg.portions. of; the. base plate, .m; shmvm in.

.2: which: iilnstrates; the;

Y result is that shown.

corelframe. assemblyseparate and; apart from; the balance or the device,the; hook: ends of the metallic strap. are: received in the grooves" .W-M thereby drawing." the base. plate: 24' against the pad andihold'ing'the latter in; slight compression, against the; underside: of: the: coreframe In order: to receiverthe: operating extension. or stem portion 32'on the lower end of the plunger or armature, the pad: 614' and the. baseportion 68 of the; metallic strap are provided. with holes 76 and i8.respectively which in assembled position align with. one another and thehole 30 in the base plate.

The u-shaped fastenerv 6B is applied to the solenoid. core frame. by a.snap-on action. The

base.- plate 24 and. the pad. 64 are first cradled on thebaseportion 6dof the fastener. The leg portions F9949; on the fastener areslid instraddling elation onto the coreframe l0, and in the course of thisassembly operation thev leg portions are resistantly spread apart to adiverging angle'as the: rolled-in ends TZE1Z ride. on the core frame.In. the final. assembled position, the turned-in. ends 12-42, snap.into. the grooves 'M'M. The

in Fig. 2' wherein the inof the fastener act to resiliently urge; thebase plate: toward the core frame and place the pad under initialcompression. the snap-on functionability' of the fastener enwardlyrolled ends ables; it.- to be, uickly installed upon: and: detached its;mounting on theasolenoi'di.

base plate is utilized to mount the solenoi'ti: assembly on any suitablesupport; There is in Fig. 3: a. plurality of posts: 86 arranged to" hereceived? in and support the-four corners of the. base plate. The:projecting stem portion of the. plunger: is: centrally disposed amongtheposts". ior operating connectionwith an object to be moved by thesolenoid;

As: a. result of this armature or plunger'at the opposite ends of itsstroke;. The impact of the plunger against the backstop; plate is takenby the resilient 5 1 The, latter serves to cushion or float the frame onthe base plate: The snap-on metallic strap-6.6 eliminates any directrigid connectionbetween the core frame and base plate; such soldering orand thereby's-aves time labor phi-ch would-be otherwise'consuined inconnccti g= these-parts together. In addition to absorbing the: shock ofi-inpact of the plunger against the frame; the resilientmaterial ofwhich the padi 5'4- is formed serves as: an insulating me dium andprevents shorting of the. laminations of'the frainea reducesthe wattageloss and;

thahe'at generated by-"the- What I claim is i an electrinclnding stator;and g there. r, being provided? with pas arou-nol'thewinding on 0.11-

posite sides thereofand' upwardly thereheyond,

an armature-having a shank portion adapted; to

use ofthe solenoid.

move" into said winding and further having a gagement of the headportion of the armature against the pole extensions, and tensioningmeans clamping the base plate to the stator and placing the resilientpad under initial compression.

2. In a solenoid, a coil winding, a C-shaped core frame extending aroundthe coil winding, a reciprocating magnetically attractable plungerhaving a shank portion extending into the coil winding and having awidened head portion adapted to strike the core frame at one end of itsstroke, a back stop plate positioned across the path of travel of theplunger in spaced relation to the core frame and adapted to be struck bythe plunger at the opposite end of its stroke, a base plate for mountingthe solenoid on a fixed support, a pair of side plates overlapping twoop posite sides of the core frame and connected therewith, said sideplates coupled with the back stop plate through resilient shockabsorbing means tensioning the back stop plate through said shockabsorbing means toward the core frame, resilient shock absorbing meansinterposed between the core frame and the base plate, a U-shaped clampembracing the base plate and overlapping two other opposite sides of thecore frame and connected therewith tensioning the base plate throughsaid shock absorbing means against the core frame.

3. In a solenoid, a coil winding, a c-shaped core frame generallysurrounding the coil winding, a reciprocating magnetically attractableplunger having a shank portion extending into the coil Winding andfurther having a widened head portion adapted to strike one end of thecore frame at the inner end of its stroke, a back stop plate positionedacross the path of travel of the head portion of the plunger on the sidethereof opposite to the core frame and adapted to be struck by the headportion at the outer end of its stroke, mechanism connecting the backstop plate with opposite sides of the core frame including resilientcushioning means adapted to absorb the shock of the plunger striking theback stop plate, a base plate for mounting the solenoid on a fixedsupport, said base plate underlying the end of the core frame oppositeto that struck by the head portion of the plunger, a flat pad ofresilient cushioning material interposed between and facially engagingthe base plate and the adjacent end of the core frame and operable toabsorb the shock of the striking engagement of the head portion of theplunger against the core frame, and a flexible metallic strap enclosingthe base plate and opposite side portions of the core frame, theopposite ends of the strap being detachably connected to the core frameand acting to hold the base plate against the pad tensioning the sametoward the core frame through the flat resilient pad.

4. In a solenoid, a coil winding, a generally C-shaped core frameextending around the coil winding, a reciprocatingly magneticallyattractable plunger having a shank portion extending into the coilwinding and further having a widened head portion adapted to strike oneend of core frame at the inner end of its stroke, a base plate formounting the solenoid on a fixed support, detachable resilient meansyieldably drawing the base plate against the underside of the coreframe, and a flat pad of resilient material interposed between andfacially engaging the base plate and the underside of the core frame,said pad being operable to absorb the shock of the striking engagementof the head portion of the plunger against the core frame.

5. In an electromagnet including a core frame and a magneticallyattractable plunger reciprocatingly mounted in the frame, a pair of sideplates for the core frame positioned on opposite sides thereof, a backstop plate overlying the upper end of the core frame and extendingacross the path of movement of the plunger so as to be struck by theplunger at the outer end of its stroke, said back stop plate having theopposite side marginal portions juxtaposition with respect to the uppermarginal portions of the side plates, resilient means interposed betweenthe juxtapositioned marginal portions of the back stop plate and'theside plates and acting to absorb the shock of the striking engagement ofthe plunger against the back stop plate, a. base plate underlying thelower end of the core frame opposite to the back stop plate, andresilient means interposed between the base plate and the lower end ofthe core frame and functioning to absorb the shock of the strikingengagement of the plunger against the core frame at the inner end of itsstroke.

6. In an electromagnet including a core frame and a magneticallyattractable plunger vertically reciprocatingly mounted in the frame, apair of side plates for the core frame positioned on two opposite sidesthereof, a back stop plate overlying the upper end of the core frame andextending across the path of movement of the plunger so as to be struckby the plunger at the outer end of its stroke, said back stop platehaving the opposite side marginal portions thereof projecting intojuxtaposition with respect to the outer marginal portions of the sideplates, cushioning means interposed between the juxtapositioned marginalportions of the back stop plate and the outer marginal portions of theside plates and acting to absorb the shock of the striking engagement ofthe plunger against the back stop plate, a base plate underlying thelower end of the core frame, a pad of cushioning material interposedbetween the base plate and the lower end of the core frame andfunctioning to absorb the shock of the striking engagement of theplunger against the core frame at the inner end of its stroke, and agenerally U-shaped flexible metallic strap embracing the two remainingopposite sides of the core frame and extending around the base plate,and means connecting the strap to the core frame and drawing the baseplate compactly against the pad.

7. In an electromagnet, an energizing coil having an end opening centralpassage therein, a core frame having pole extensions extending along theoutside of said coil and parallel to the axis of its passage, anarmature for the electrom-agnet including a shank portion adapted toreciprocate in said passage of the coil and having a widened headportion adapted to overlie the upper ends of said pole extensions andstrike the same when the plunger is attracted by energiza tion of thecoil, a base plate underlying the base of the core frame on the sidethereof opposite to the widened head portion of the armature, a fiat pad'of cushioning material interposed between the base plate and the baseof the core frame, means detachably connecting the base plate to thecore frame and acting to yieldingly draw the base plate toward the coreframe to compactly hold the pad between the base plate and the adjacentend of the core frame, aback stop plate overlying the head end of thearmature spaced from the ends of the pole extensions,

means interconnecting opposite sides of the back.

thereof projecting into stop plate with the core frame, and resilientcushioning elements interposed between said means and the back stopplate.

8. In an electromagnet, an energizing coil having an end opening centralpassage therein, a core frame having pole extensions extending along theoutside of said coil and parallel to the axis of its passage, anarmature for the electromagnet including a shank portion adapted toreciprocate in said passage of the coil and having a widened headportion adapted to overlie the upper ends of said pole extensions andstrike the same when the plunger is attracted by energization of thecoil, a base plate underlying the core frame and disposed on the sidethereof opposite to the widened head portion of the armature, a flat padof cushioning material interposed between the base plate and theadjacent end of the core frame, a generally U-shaped member embracingtwo opposite sides of the core frame and extending around the baseplate, the ends of the arms of the U-shaped member being bent intoengagement with the core frame and acting to draw the base plate towardthe core frame to compactly hold the pad between the base plate and theadjacent end of the core frame, a generally U-shaped assembly the baseof which comprises a back stop plate and the arms of which extend fromopposite sides of the back stop plate and embrace two other oppositesides of the core frame and are secured thereto and resilient cushioningmeans interposed in the connection between the back stop plate and saidarms.

9. In a solenoid, a coil winding having a central passageway, a coreframe having pole portions extending along two opposite sides of saidcoil, a plunger having a shank portion disposed to reciprocate in thecoil passageway and having a head portion adapted to overlie the ends ofthe pole portions and to strike the same at one end of the stroke of theplunger, a base plate overlying the opposite end of the core frame, apad of resilient cushioning material interposed between the base plateand the core frame, a U- shaped spring clamp embracing the base plateand having its two arms overlapping the two opposite sides of the coreframe the ends of said arms being bent into engagement with the coreframe tensioning the base plate against the pad and toward the coreframe, a generally U-shaped back stop plate assembly the base of whichassembly comprises a back stop plate proper disposed across the path oftravel of the plunger above the head of the plunger to be struck therebyat the opposite end of the stroke of the plunger and a pair of armlikeextensions for the back stop plate proper depending therefrom andoverlapping two other opposite sides of the core frame and connectedtherewith, said back stop plate assembly including resilient cushioningmeans adapted to absorb the impact of the plunger against the back stopplate.

10. A solenoid as defined in claim numbered 1, characterized in that thestator is provided on opposite sides with depending portions overlappingopposite edges of the pad of resilient material which is interposedbetween the stator and the base plate.

11. A solenoid as defined in claim numbered 9, characterized in that thecore frame is provided on opposite sides with depending portionsoverlapping opposite edges of the pad which superposes the base plateand the base plate is provided with a recess on its underside in whichthat portion or" the U-shaped clamp which embraces the base plate isdisposed.

HOLLIS W. JENCKS.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES McCurry et a1., Abstract Ser. No. 90,412, published March 20,1951.

